2: Pathology of the thyroid gland Flashcards Preview

Endocrine Week 3 2017/18 > 2: Pathology of the thyroid gland > Flashcards

Flashcards in 2: Pathology of the thyroid gland Deck (60)
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1
Q

At what level is the thyroid gland found?

A

C5 - T1

2
Q

Where does the thyroid gland start out during development?

Through which hole in the tongue does it move inferiorly?

Which passage carries it to the neck?

A

Tongue

Foramen caecum

Thyroglossal duct

3
Q

What is a thyroid called when it fails to descend through the thyroglossal duct?

A

Lingual thyroid

4
Q

If the thyroid gland descends too much during development, where can it end up?

A

Mediastinum

behind the sternum

5
Q

What is a thyroglossal duct cyst?

A

Benign growth which moves with swallowing

6
Q

The thyroid gland is an endocrine organ composed of ___, where the thyroid hormones are produced.

A

follicles

7
Q

What chemical is found in thyroid follicles?

A

Thyroglobulin

8
Q

Which cells produce T3 and T4?

A

Follicular cells

9
Q

Which cells are found next to follicles and secrete calcitonin?

A

C cells (parafollicular cells)

10
Q

hypothalamus

trh

anterior pituitary

tsh

thyroid gland

t3 and t4

target cells

A
11
Q

When T3 / 4 levels are high, the secretion of hormones along the h.p.t axis is (increased / suppressed).

A

suppressed

12
Q

What type of receptor are TSH receptors?

A

G protein receptors

Release of T3 and T4 are controlled by cyclic AMP

13
Q

What do the thyroid hormones do?

A

Regulate metabolic rate

14
Q

What happens to the size of the thyroid gland when it is

a) hyperactive
b) underactive?

A

hyperactive - enlarged

underactive - atrophied

15
Q

What is thyroiditis?

A

Inflammation of the thyroid gland

16
Q

Which type of thyroiditis causes hypofunction?

A

Hashimoto’s

17
Q

What kind of thyroiditis causes hyperfunction?

A

Graves disease

18
Q

Hashimoto’s disease causes ___thyroidism.

A

hypothyroidism

19
Q

Graves disease causes ___thyroidism.

Why?

A

hyperthyroidism

Disease stimulates thyroid gland

20
Q

Autoimmune thyroiditis has a large ___ component.

A

genetic

21
Q

What are some genes associated with autoimmune thyroiditis?

A

CTLA-4

PTPN-22

22
Q

What state occurs as a result of excess thyroid hormone in hyperthyroidism?

A

Thyrotoxicosis

23
Q

Apart from hyperthyroidism, what else can cause thyrotoxicosis?

A

Thyroiditis

Ectopic thyroid gland

24
Q

What is the most common cause of hyperthyroidism?

A

Graves disease

25
Q

Apart from Graves disease, hyperthyroidism can also be caused by ___.

A

tumours

of both thyroid and other organs e.g pituitary

26
Q

Graves disease is more common in (men / women).

A

women

27
Q

What antibody is associated with Graves disease?

A

TSH receptor antibodies

28
Q

What are the three main features seen in Graves disease?

A

Hyperthyroidism

Eye changes

Pretibial myoxedema (leg swelling)

29
Q

What is the main cause of hypothyroidism?

A

Hashimoto’s thyroiditis

30
Q

As with Graves and other thyroid diseases, Hashimoto’s thyroiditis mainly affects ___.

A

women

31
Q

What are some other causes of hypothyroidism apart from Hashimoto’s?

A

Iodine deficiency

Drugs

Congenital

Tumours

32
Q

Hashimoto’s thyroiditis involves a (sudden / gradual) change in thyroid function.

A

gradual failure

33
Q

Which autoantibodies are raised in Hashimoto’s thyroiditis?

A

Anti-PTO antibodies (main ones)

Anti-thyroglobulin

34
Q

Which cells are responsible for autoimmune destruction of the thyroid gland in Hashimoto’s thyroiditis?

A

T lymphocytes

35
Q

Why are autoimmune thyroid conditions sometimes paradoxical?

A

Often there are short periods of HYPO in Graves and HYPER in Hashimoto’s

36
Q

What cancer are people with Hashimoto’s thyroiditis at risk of?

A

Non-Hodgkins lymphoma of thyroid

37
Q

What is a goitre?

A

Enlargement of thyroid gland

38
Q

What commonly causes goitre?

A

Iodine deficiency

39
Q

How do goitres occur in terms of iodine deficiency?

A

Reduced T3 / T4 production

Increased levels of TSH

Thyroid enlargement

40
Q

Goitre is commonly associated with (hypo / hyperthyroidism).

A

hypothyroidism

41
Q

What types of benign neoplasm can arise in the thyroid gland?

A

Adenomas - glandular tumours

42
Q

Adenomas of the thyroid are derived from the ____ epithelium.

A

follicular

43
Q

What type of malignant neoplasm arises in the thyroid?

A

Carcinomas

44
Q

papillary

follicular

medullary - from c cells

anaplastic - wild, poor prognosis

A
45
Q

What do thyroid adenomas look like?

A

Discrete

Solid

46
Q

Benign thyroid adenomas are surrounded by a thick sheet of ___ which is well circumscribed.

A

collagen

47
Q

Do thyroid adenomas function like normal thyroid tissue?

A

Usually non-functional

48
Q

Are thyroid carcinomas common?

A

No

1.5% of all cancers

49
Q

Most thyroid carcinomas come from the follicular epithelium.

Where do medullary carcinomas come from?

A

C cells

50
Q

What is the most common type of thyroid carcinoma?

A

Papillary carcinoma

51
Q

What are some associations with

a) papillary carcinoma
b) follicular carcinoma?

A

a) Ionising radiation e.g Chernobyl disaster

b) Iodine deficiency

52
Q

Papillary carcinomas commonly spread through which system?

What may you find on general examination?

A

Lymphatic system

Enlarged lymph nodes

53
Q

What symptoms do papillary carcinomas cause when enlarged?

A

Hoarseness

Dysphagia

Cough

Dyspnoea

54
Q

Onset of symptoms suggest a (basic / advanced) papillary carcinoma.

A

advanced

55
Q

Papillary carcinomas usually have a (good / bad) prognosis.

A

Good

95% live beyond 10 years

56
Q

What is the second most common thyroid cancer?

A

Follicular carcinoma

57
Q

Do follicular carinomas spread via the lymphatic system?

A

No, via bloodstream

58
Q

Which type of thyroid carcinoma is derived from C cells?

A

Medullary carcinoma

59
Q

What type of thyroid tumour is extremely aggressive and is least common?

A

Anaplastic carcinoma

60
Q

What is the mortality of anaplastic carcinoma?

A

100%